Genetic modification of plants has, in combination with conventional breeding programs, led to significant increases in agricultural yield over the last decades. Genetically modified plants may be selected for one or more agronomic traits, for example by expression of enzyme coding sequences (e.g., enzymes that provide herbicide resistance). Genetic manipulation of genes involved in plant growth or yield may enable increased production of valuable commercial crops, resulting in benefits in agriculture and development of alternate energy sources such as biofuels.
Plant biomass content has recently become an intense area of research due to the broad ranging commercial applications for such technology. For example, biofuel is increasingly being considered as a renewable, cleaner alternative to petroleum-based fuels. A variety of fuels may also be produced from sugars and starches as well as from lignocellulosic-based biomass, which constitute the most abundant biomass on earth. However, the types of biofuels that can be efficiently produced from plant mass depend upon the content of component materials such as lignin. Likewise, biomass content dictates the nutritional value of plant mass as animal feed. In particular, high lignin content in plant matter can result in animal feed that is difficult for livestock to digest. Development of plants with modified cell wall composition would have a significant benefit for the production of biofuels and animal feeds and could potentially have a broad range of other beneficial applications. However genetic modification of plants to achieve these goals has not been realized.